Make sure all local Zarafa users are also available in the Active Directory or OpenLDAP directory. The usernames used with the DB plugin, should be the same as the username in AD/LDAP.

Install the perl module MIME::Base64 and DBI

Make sure you have a successful backup of the Zarafa database

Execution:

Shutdown Zarafa (which is configured for DB plugin)

Run the db-to-ldap-plugin.pl script

Configure Zarafa for the LDAP plugin

Start Zarafa (with new LDAP plugin)

When this script is successfully executed, run the db-upgrade-addressbook-entryids.pl to fix all entries of all email items

Test if you can still reply internal emails from before the migration

Test if access to shared mailboxes is still working

NOTE: This is not officially supported. Zarafa Professional Services can help you with these upgrade processes. The order of execution is very important, the key is to have Zarafa not noticing that the "externid" of the "users" table have changed.

NOTE: If you want to try this yourself, please try it first in a test environment if you don't then you might end up with all the mailstores unhooked on your production environment.